Laser printers and electrostatic copiers employ toner cartridges that contain a supply of toner material for use during the electrostatic development process. The cartridges are designed to be replaced from time to time, to replenish the toner that is used during the printing process. Such toner cartridges include an elongated toner container (called a "bottle") and a cover that includes a charging rod and an electrostatic magnetic roller assembly. The bottle and cover have flanges that mate and are bonded along their elongated dimensions to create a singular cartridge structure. At one end of the cartridge, the flanges are not bonded, but rather include a foam seal through which a toner "dam" tear strip extends. When the toner cartridge is first used, the tear strip is removed by pulling it through the foam seal, thereby causing removal of an internal dam that covers the bottle portion of the cartridge, thereby rendering accessible the toner contained therein.
While toner cartridges were initially designed to be discarded after the original toner supply was exhausted, certain cartridge portions, (i.e., the magnetic roller and charging rod) have longer useful lives. Thus, a market has developed for refurbished cartridges that have been refilled with a supply of toner. However, replacement toner dams have generally been unsatisfactory as they have enabled leakage of refilled toner.
In copending U.S. application Ser. No. 08/071,909 entitled "TONER CARTRIDGE TONER DAM REPLACEMENT AND METHOD THEREFOR", a plurality of improved toner dams and methods for their insertion into used toner cartridges are disclosed. U.S. Pat. No. 5,080,745 to Paull also discloses a replacement toner dam for insertion into a used toner cartridge. Each of the toner dams shown in the above noted copending application and in Paull require either the insertion of a replacement toner dam through the above described foam seal in the end of a cartridge or, require disassembly of the cartridge.
All toner cartridges are provided with a fill opening at one end through which toner is initially loaded during manufacture. If a new toner dam could be inserted through the fill opening, the resulting refurbishment procedure would be simplified over that shown in the prior art.
Accordingly, it is an object of this invention to provide a simplified means for refurbishing a used toner cartridge.
It is another object of this invention to provide a method for refurbishing a used toner cartridge wherein a need for replacement of the toner dam is obviated.
It is yet another object of this invention to provide a method for refurbishing a used toner cartridge, which method is both simple and inexpensive.